Relative sensitivity of the corpus luteum of different days of pregnancy to LH-deprivation in the rat and hamster

Deprivation of endogenous LH by LH antiserum (LH A/S) in 6-day pregnant rats did not affect the luteal or serum progesterone within 24 h. LH A/S treatment on day 7 or 8 of pregnancy, however, caused a 70 and 92% reduction in luteal progesterone, respectively, within 24 h. Serum levels of progesterone showed a similar reduction. In the case of pregnant hamster, unlike the rat, there was a significant decrease in progesterone in the serum, luteal and non-luteal compartments whether the A/S was administered on day 4, 5 or 6. There was more than a 10-fold increase in the luteal cholesterol esters within 24 h whether the A/S was given on day 6, 7 or 8 of pregnancy in the rat. Rat corpora lutea of days 6 and 8 of pregnancy reacted in a like manner to LH-deprivation, showing an increased utilization of [U-14C]glucose to form 14CO2 in vitro. In the rat, LH (25 μg NIH-S19) administration in vivo either on day 6 or day 8 of pregnancy, caused within 2 h an increase in serum and non-luteal progesterone, but luteal progesterone was unchanged. On the other hand, LH administration to hamsters on day 8 of pregnancy caused an increase in progesterone levels in serum, luteal and non-luteal tissue. Incubation of corpora lutea isolated from untreated 6- and 8-day pregnant rats with LH brought about an increase in progesterone secretion into the medium in both cases. The results show that, even though LH-deprivation does not apparently affect progesterone concentration in the corpus luteum of 6-day pregnant rats, it does affect other metabolic parameters such as glucose utilization and cholesterol turnover, suggesting that the corpus luteum of early pregnancy exhibits a continuous dependency on LH for the maintainence of metabolic functions.

Climate response to changes in atmospheric carbon dioxide and solar irradiance on the time scale of days to weeks

Recent studies show that fast climate response on time scales of less than a month can have important implications for long-term climate change. In this study, we investigate climate response on the time scale of days to weeks to a step-function quadrupling of atmospheric CO2 and contrast this with the response to a 4% increase in solar irradiance. Our simulations show that significant climate effects occur within days of a stepwise increase in both atmospheric CO2 content and solar irradiance. Over ocean, increased atmospheric CO2 warms the lower troposphere more than the surface, increasing atmospheric stability, moistening the boundary layer, and suppressing evaporation and precipitation. In contrast, over ocean, increased solar irradiance warms the lower troposphere to a much lesser extent, causing a much smaller change in evaporation and precipitation. Over land, both increased CO2 and increased solar irradiance cause rapid surface warming that tends to increase both evaporation and precipitation. However, the physiological effect of increased atmospheric CO2 on plant stomata reduces plant transpiration, drying the boundary layer and decreasing precipitation. This effect does not occur with increased solar irradiance. Therefore, differences in climatic effects from CO2 versus solar forcing are manifested within days after the forcing is imposed.

Gossypol-induced hypokalemia and role of exogenous potassium salt supplementation when used as an antispermatogenic agent in male langur monkey

In our earlier study, we have observed that hypokalemia in langur monkeys, following gossypol acetic acid (GAA) treatment (5 mg dose level) when used as an antispermatogenic agent, and potassium salt supplementation partially maintained body potassium level of the animals. The aims of the present investigation was to confirm further occurrence of hypokalemia in the monkey (comparatively at two higher dose levels) and the role of potassium salt in preventing occurrence of gossypol-induced hypokalemia. Highly purified gossypol acetic acid alone at two dose levels (7.5 and 10 mg/animal/day; oral) and in combination with potassium chloride (0.50 and 0.75 mg/animal/day; oral) was given for 180 days. Treatment with gossypol alone as well as with the supplementation of potassium salt resulted in severe oligospermia and azoospermia. Animals receiving gossypol alone showed significant potassium deficiency with signs of fatigue at both dose levels. Enhanced potassium loss through urine was found in potassium-deficient animals, whereas animals receiving gossypol acetic acid plus potassium salt showed normal serum potassium with a less significant increase in urine potassium level during treatment phases. Other parameters of the body remained within normal range except gradual and significant elevation in serum transaminases activity. The animals gradually returned to normalcy following 150 and 180 days of termination of the treatment.

Immunization of male bonnet monkeys (M-radiata) with a recombinant FSH receptor preparation affects testicular function and fertility

Immunization of proven fertile adult male monkeys (n = 3) with a recombinant FSH receptor protein preparation (oFSHR-P) (representing amino acids 1-134 of the extracellular domain of the receptor Mr similar to 15KDa) resulted in production of receptor blocking antibodies. The ability of the antibody to bind a particulate FSH receptor preparation and receptors in intact granulosa cells was markedly (by 30-80%) inhibited by FSH. Serum T levels and LH receptor function following immunization remained unchanged. The immunized monkeys showed a 50% reduction (p<0.001) in transformation of spermatogonia(2C) to primary spermatocytes (4C) as determined by flow cytometry and the 4C:2C ratio showed a correlative change (R 0.81, p<0.0007) with reduction in fertility index (sperm counts X motility score). Breeding studies indicated that monkeys became infertile between 242-368 days of immunization when the fertility index was in the range of 123+/-76 to 354+/-42 (compared to a value of 1602+/-384 on day 0). As the effects observed ate near identical to that seen following immunization with FSH it is suggestive that oFSHR-P can substitute for FSH in the development of a contraceptive vaccine.

Metabolism of geraniol and linalool in the rat and effects on liver and lung microsomal enzymes

1. Metabolites isolated from the urine of rats after oral administration of geraniol (I) were: geranic acid (II), 3-hydroxy-citronellic acid (III), 8-hydroxy-geraniol (IV), 8-carboxy-geraniol (V) and Hildebrandt acid (VI). 2. Metabolites isolated from urine of rats after oral administration of linalool (VII) were 8-hydroxy-linalool (VIII) and 8-carboxy-linalool (IX). 3. After three days of feeding rats with either geraniol or linalool, liver-microsomal cytochrome P-450 was increased. Both NADH- and NADPH-cytochrome c reductase activities were not significantly changed during the six days of treatment. 4. Oral administration of these two terpenoids did not affect any of the lung-microsomal parameters measured.

A Need for FSH in Maintaining Fertility of Adult Male Subhuman Primates

Adult fertile male bonnet monkeys (Macaca radiata) were continuously deprived of endogenous follicle stimulating hormone (FSH) support for 240 days by injecting them with 1 ml of characterized monkey antiserum to oFSH every 48 hr; control monkeys received during the same period normal monkey serum instead. Testicular function was assessed at periodic intervals by (a) carrying out differential counting of sperm in the ejaculate obtained and (b) determining the hyaluronidase activity as well as in vitro 3H thymidine incorporation into DNA of testicular tissue removed at biopsy. Both the quality (viability and motility) of the sperms voided and the total sperm counts showed marked decreases as a function of time of immunization, the first significant reduction being noted by 100 days. FSH deprivation affected both the biochemical parameters used to test testicular functionality they being reduced at ∼200 days by 50%-60%. The fertility of these monkeys was evaluated at periodic times after 90 days of treatment by means of mating studies. FSH deprivation had rendered the monkeys incapable of impregnating any of the females used. Testosterone and luteinizing hormone (LH) levels remained unchanged following FSH antiserum injection. With cessation of antiserum treatment testicular function and fertility were completely restored to normalcy, indicating that the observed effect was specifically due to FSH deprivation. This study thus provides conclusive evidence for the involvement of FSH in maintenance of testicular function and fertility in the adult male primate.

Effect of human chorionic gonadotropin on serum levels of progesterone and estrogens in the pregnant bonnet monkev (Macaca radiata)

Administration of human chorionic gonadotropin to pregnant bonnet monkeys (Macaca radiata) at 55-60 days and 130-140 days of pregnancy resulted in a significant increase in serum progesterone levels. This effect could be observed even in lutectomized monkeys.However, no significant change in the serum estrogen level was noticed. These results suggest that although no chorionic gonadotropin is detectable in the serum after 35 days of pregnancy, the foetoplacental steroidogenic system is still responsive to exogenous gonadotropic stimulation.

Use of norethisterone and estradiol in mini doses as a contraceptive in the male : Efficacy studies in the adult male bonnet monkey (Macaca radiata)

Administration of norethisterone (NET) or NET + estradiol benzoate using an Alzet minipump or as once-a-month intramuscular injection of their depot forms, NET-enanthate (NET-EN) and estradiol valerate (E-val), resulted in azoospermia in all monkeys (n = 13) within 60 to 150 days of treatment. Although addition of depot form of testosterone (T, 20 mg/month) to the regimen restored the behavioral response typical of a normal male, it did not reverse the azoospermic state. Serum T (heightened nocturnal) levels were significantly reduced (> 85%, p < 0.001) in all the treated groups. Evidence for blockade in spermatogenesis following treatment was obtained by DNA flow cytometry. Following withdrawal of treatment, the T level was restored to normalcy within 15 days but 120 days more were required for the animals to exhibit normal sperm counts. In conclusion, the efficacy of once-a-month injection of relatively low doses of NET-EN + E-Val to bring about azoospermia in monkeys, in a relatively short time, has been demonstrated. As the results are uniform and reproducible, it appears desirable that this steroid regimen be tested in man for its contraceptive efficacy.

Biotransformation of cholesterol to diosgenin by freely suspended and immobilised cells of Dioscorea bulbifera L.

The cell suspension cultures, established from the friable callus which was risen from the nodal segments of Dioscorea bulbifera L. in Murashige-Skoog (MS) medium supplemented with indole-3-butryic acid (20 mg L- 1), was examined for cell growth in MS medium fed with cholesterol (50 mg L- 1 and 100 mg L- 1) after 8, 10, 12, 14, 16, and 18 days of culture. The growth index of the cell suspension culture on the 8th day was 1.2 and gradually inclined to 1.9 on the 16th day and remained the same at the 18th day. There is no marked difference in the cell growth of cholesterol-treated and control cell suspension culture. The maximum accumulation of diosgenin was noticed on the 14th day in control and cholesterol-treated cell suspension culture and immobilised cell cultures. The highest concentration of diosgenin, 2.94% and 2.14% dry weight, was obtained in immobilised cell culture and cell suspension culture treated with 100 mg L- 1 cholesterol, respectively.

Effect of ICSH on Early Pregnancy in Hypophysectomized Pregnant Rats

Moudgal and co-workers1-3 recently reported that the administration to intact pregnant rats of rabbit antiserum ovine interstitial cell stimulating hormone (ICSH) on any one day between the eighth and twelfth days of pregnancy resulted in resorption of foetuses and termination of pregnancy. This effect was readily reversed by the simultaneous administration of progesterone but not by oestradiol-17β. These observations suggested that ICSH was involved in progesterone synthesis and as such is a luteotropic factor in the rat.

Active and break spells of the Indian summer monsoon

In this paper, we suggest criteria for the identification of active and break events of the Indian summer monsoon on the basis of recently derived high resolution daily gridded rainfall dataset over India (1951-2007). Active and break events are defined as periods during the peak monsoon months of July and August, in which the normalized anomaly of the rainfall over a critical area, called the monsoon core zone exceeds 1 or is less than -1.0 respectively, provided the criterion is satisfied for at least three consecutive days. We elucidate the major features of these events. We consider very briefly the relationship of the intraseasonal fluctuations between these events and the interannual variation of the summer monsoon rainfall. We find that breaks tend to have a longer life-span than active spells.While, almost 80% of the active spells lasted 3-4 days, only 40% of the break spells were of such short duration. A small fraction (9%) of active spells and 32% of break spells lasted for a week or longer. While active events occurred almost every year, not a single break occurred in 26% of the years considered. On an average, there are 7 days of active and break events from July through August. There are no significant trends in either the days of active or break events. We have shown that there is a major difference between weak spells and long intense breaks. While weak spells are characterized by weak moist convective regimes, long intense break events have a heat trough type circulation which is similar to the circulation over the Indian subcontinent before the onset of the monsoon. The space-time evolution of the rainfall composite patterns suggests that the revival from breaks occurs primarily from northward propagations of the convective cloud zone. There are important differences between the spatial patterns of the active/break spells and those characteristic of interannual variation, particularly those associated with the link to ENSO. Hence, the interannual variation of the Indian monsoon cannot be considered as primarily arising from the interannual variation of intraseasonal variation. However, the signature over the eastern equatorial Indian Ocean on intraseasonal time scales is similar to that on the interannual time scales.

Studies on the metabolism of l-menthol in rats

Metabolism of l-menthol in rats was investigated both in vivo and in vitro. Metabolites isolated and characterized from the urine of rats after oral administration (800 mg/kg of body weight/day) of l-menthol were the following: p-menthane-3,8-diol (II), p-menthane-3,9-diol (III), 3,8-oxy-p-menthane-7-carboxylic acid (IV), and 3,8-dihyroxy-p-menthane-7-carboxylic acid (V). In vivo, the major urinary metabolites were compounds II and V. Repeated oral administration (800 mg/kg of body weight/day) of l-menthol to rats for 3 days resulted in the increase of both liver microsomal cytochrome P-450 content and NADPH-cytochrome c reductase activity by nearly 80%. Further treatment (for 7 days total) reduced their levels considerably, although the levels were still higher than the control values. Both cytochrome b5 and NADH-cytochrome c reductase levels were not changed during the 7 days of treatment. Rat liver microsomes readily converted l-menthol to p-menthane-3,8-diol (II) in the presence of NADPH and O2. This activity was significantly higher in microsomes obtained from phenobarbital (PB)-induced rats than from control microsomal preparations, whereas 3-methylcholanthrene (3-MC)-induced microsomes failed to convert l-menthol to compound II in the presence of NADPH and O2. l-Menthol elicited a type I spectrum with control (Ks = 60.6 microM) and PB-induced (Ks = 32.3 microM) microsomes whereas with 3MC-induced microsomes it produced a reverse type I spectrum.

Development stage-specific expression of fibroin in the silk worm Bombyx mori is regulated translationally

The contents of fibroin H RNA as a function of development have been quantitated in the posterior silk glands of Bombyx mori larvae on different days of 4th and 5th instars. The fibroin RNA levels increased during the feeding stages of larvae and the RNA got completely degraded during the interim moult. The patterns of accumulation of fibroin RNA were similar in both the instars. Although there was considerable increase in the fibroin RNA content during the 5th larval instar, the relative abundance of fibroin RNA in the total RNA was fairly constant during the 4th and 5th instars. The increased content of fibroin RNA in 5th instar was the consequence of an overall increase in transcription accompanying the development progress, rather than specific increase only in fibroin transcription. The contents of fibroin protein in the 4th and 5th instars of development have also been quantitated making use of a sensitive radioimmune assay with a purified, antifibroin antibody. There were substantial differences between 4th and 5th instars in the absolute fibroin contents as well as the relative proportion of fibroin in the total proteins. These results implied that although the fibroin gene was transcribed at the same efficiency during the 4th and 5th instars, the translational efficiency was much lower during the 4th instar. The extent of polyadenylation of fibroin RNA was similar in both instars. However, there was a two-fold increase in the polysome association of fibroin RNA in the 5th instar. Over and above this, there was substantial increase during the 5th instar in the contents of those tRNAs. (e.g. Gly, Ala and Ser) which are abundantly represented in fibroin and therefore directly related to the expression of fibroin. The increased polysome association of fibroin mRNA and the adequate supply of cognate tRNAs in the 5th instar, together contributes to the translational regulation of fibroin in a developmental stage-specific manner. Based on these observations, we propose that translational regulation plays a major role in the development stage-specific synthesis of fibroin in Bombyx mori.

Studies on neurotransmitter-stimulated phospholipid metabolism with cerebral tissue suspensions: A possible biochemical correlate of synaptogenesis in normal and undernourished rats

The phenomenon of neurotransmitter-stimulated incorporation of32Pi into phosphatidic acid and inositol phosphatides (neurotransmitter effect) in developing brain was studied in vitro as a possible measure of synaptogenesis. While the neurotransmitter effect was not observed with brain homogenates, highly consistent and significant effects were noted with brain tissue suspensions obtained by passing the tissue through nylon bolting cloth. The magnitude of the effect decreased with the increase in mesh number. Maximum stimulations obtained with the 33 mesh adult brain cortex preparations (mean±S.E.M. of6experiments) were203 ± 8%, 316 ± 11 % and150 ± 8% with 10−3 M acetylcholine (ACh) + 10−3 M eserine; 10−2 M norepinephrine (NE) and 10−2 M serotonin (5-HT), respectively. Experiments with developing rat brain at 7, 14 and 21 days of age showed that the neurotransmitter effects due to ACh, NE and 5-HT increase progressively in different regions of the brain but that there are marked regional differences. It is suggested that the neurotransmitter effect is a valid biochemical correlate of synaptogenesis. In rats undernourished from birth t0 21 days of age, by increasing the litter size, the neurotransmitter effect with ACh, NE or 5-HT was not altered in the cortex but was significantly reduced in the brain stem. In cerebellum the effects due to ACh and NE were significantly altered, while that with 5-HT was unaffected. It is concluded that cholinergic, adrenergic and serotonergic synapses are relatively unaffected in the cortex but are significantly affected in the brain stem by undernutrition. In the cerebellum of undernourished rats the adrenergic and cholinergic, but not serotonergic systems, are altered.

Thermodynamics of Phosphorus and Sulphur Removal during Basic Oxygen Steelmaking

Removal of impurity elements from hot metal is essential in basic oxygen steelmaking. Oxidation of phosphorus from hot metal has been studied by several authors since the early days of steelmaking. Influence of different parameters on the distribution of phosphorus, seen during the recent work of the authors, differs somewhat from that reported earlier. On the other hand, removal of sulphur during steelmaking has drawn much less attention. This may be due to the magnitude of desulphurisation in oxygen steelmaking being relatively low and desulphurisation during hot metal pre-treatment or in the ladle furnace offering better commercial viability Further, it is normally accepted that sulphur is removed to steelmaking slag in the form of sulphide only However, recent investigations have indicated that a significant amount of sulphur removed during basic oxygen steelmaking can exist in the form of sulphate in the slag under oxidising conditions. The distribution of sulphur during steelmaking becomes more important in the event of carry-over of sulphur-rich blast-furnace slag, which increases sulphur load in the BOF. The chemical nature of sulphur in this slag undergoes a gradual transition from sulphide to sulphate as the oxidative refining progresses.