Pineal indoleamine metabolism in pyridoxine-deficient rats

Pvridoxine deficiency causes physiologically significant decrease in brain serotonin (5-HT) due to decreased decarboxylation of 5- hvdroxvtrvptophan (5-HTP). We have examined the effect of pyridoxine deficiency on indoleamine metabolism in the pineal gland, a tissue with high indoleamine turnover. Adult male Sprague-Dawley rats were fed either a pyridoxine-supplemented or pyridoxinedeficient diet for 8 weeks. Pyridoxine deficiency did not alter the pattern of circadian rhythm of pineal 5-HT. 5-hvdroxvindoleacetic acid (5-HIAA), V-acetvlserotonin (NAS). and melatonin. However the levels of these compounds were significantly lower in the pineal glands of pyridoxine-deficient animals. Pineal 5-HTP levels were consistently higher in the pyridoxine-deficient animals and a conspicuous increase was noticed at 22.00 h. Increase in pineal NAS and melatonin levels caused by isoproterenol (5 mg kg at 17.00 h) were significantly lower (P < 0.05) in the pyridoxine-deficient animals. Treatment of pyridoxine-deficient rats with pvridoxine restored the levels of pineal 5-HT, 5-HIAA. NAS. and melatonin to values seen in pyridoxine-supplemented control animals. These results suggest that 5-HT availability could be an important factor in the regulation of the synthesis of pineal NAS and melatonin.

Histological, Histochemical and Biochemical characterisation of male morphotypes of Macrobrachium rosenbergii (de Man)

This thesis entitled “Histological ,Histochemical and biochemical characterisation of male morphotypes of macrobrachium rosenbergii(De Man). The giant fresh water prawn Macrobrachium rosenbergii (de Man) is emerging as a prime candidate species in fresh water aquaculture as a global basis and therefore, receiving much attention in recent years.the present work was aimed at to study the histological variations, if any, in the reproductive system viz. testes, vas deferens including androgenic gland, hepatopancreas and the neurosecretory system viz. eye stalk, brain and thoracic ganglion among the male morphotypes and their transitional stages of M.rosenbergii from growouts. This study was also aimed at to bring out the histochemical variations, if any, in the reproductive system comprising of testes, vas deferens including androgenic gland and the hepatopancreas among the male morphotypes and their transitional stages collected from growouts. Biochemical characterisation of various male morphotyes and their transitional stages have also been attempted in order to find out biochemical evidence, if any, in the morphotypic transformation.Histological study of the testes of three male morphotypes viz., SM, SOC and SBC and their 'transitional stages viz., WOC, tSOC, WBC and OBC have been carried out with a view to unravel the structural and functional differences of the testes, if any, of these morphotypes. Studies on the lipid components viz., cholesterol, phospholipid and triglyceride In the muscle tissue and hepatopancreas have been carried out.

Physiology of the blood of cat fishes

The vast areas of derelict swamps covered by macrophyton and swarmed by insects scattered in different parts of India are at present either under total negligence or utilized as waste disposal dumps. Eventhough Indian subcontinent is ranked among the first ten fish producing countries in the world, the fish production is not at par with the increasing need of protein in the average Indian diet. So the water areas which become unusable for conventional human activities like the swamps could be used for fish culture which would increase the availability of protein in the form of fish flesh, thus providing new opportunities to the fishermen. But the conversion of swamps for fish culture would entail considerable expenditure. Hence the significance of a group of fresh water fishes which have made their favourable abode the muddy swamps of tropics depending partly on accessory _respiration to survive in the inimical environment. The homeostasis achieved in such a hostile, hypoxic medium make them excellent choices for culture in the derelict freshwater bodies of India. These air breathing fishes form an economically important group which are highly esteemed as food fishes in many parts of South Asia and Africa. Though their natural habitat seems to be the marshes, they have also conquered other freshwater bodies like ponds, tanks, rivers and flooded paddy fields. They can also tolerate slightly brackish waters. They are known for their nutritive, invigorating and therapeutic qualities and are recommended by physicians as diet during convalescence (Jhingran, 1982)