Effects of exposition to polluted environments on blood cells of the fish Prochilodus lineatus

In this study, we investigated the effects of contaminated water on the blood parameters of the fish Prochilodus lineatus exposed during 7 and 20 days. Blood was collected with heparinized syringes, and blood smears were prepared and stained with Leishman stain. Slides were examined and photographed using a Leica light microscope. Total white blood cell counts and differential counts of thrombocytes and leukocytes were obtained for statistical analysis. The group exposed to water samples from Lago Azul exhibited an increase in the number of leukocytes and in the total number of white blood cells, suggesting that the chemical contaminants in this environment were acting similarly to antigens in this fish species, causing the proliferation of defense cells. In the group exposed to detergent during 20 days, the number of thrombocytes decreased. These results suggest that the variations in the number of leukocytes were indicators of environmental pollution and that biodegradable detergents may, after a certain time of exposure, affect vital functions in fish, such as coagulation and prevention of infections, which directly involves thrombocytes. Microsc. Res. Tech., 2012. (c) 2011 Wiley Periodicals, Inc.

LH surge in response to the treatment with GnRH analog or estradiol in ovariectomized buffaloes with or without progesterone pre-exposition

The aim of the present study was to evaluate the LH surge after EB (estradiol benzoate) or GnRH administration with or without P4 (progesterone) pre-exposure in ovariectomized (OVX) buffalo cows. Females were randomly assigned to receive an intravaginal P4 device (D0–D9). They were then given EB 24 h or GnRH 36 h post-P4 device removal (factorial 2×2, n=6 per group). Blood collection for LH measurement began 36 h after the P4 device removal and continued at 3 h intervals. The area under the LH curve (AUC; 30.2 ng2 and 13.41 ng2; P=0.007) and the area of the LH peak (AP; 19.0 ng2 and 8.9 ng2; P=0.009) were greater for EB than GnRH. We did not observe an effect of P4 pre-exposure on the AUC and AP. Furthermore, there was no interaction between P4 pre-exposure and EB or GnRH treatment on the AUC and AP. However, there was an interaction (P<0.01) between P4 pre-exposure and the type of inducer (EB or GnRH) to release a preovulatory-like LH surge at the beginning (BP), final (FP) and time (TP) of the LH peak. The P4 pre-exposure anticipated the BP (2.5 and 7.4 h), TP (6.0 and 12.0 h) and FP (11.5 and 17.1 h) when EB was used to induce a preovulatory-like LH surge (P<0.01). However, there was no effect of P4 pre-exposure on BP (0.4 and 0.4 h), TP (3.0 and 3.0 h) and FP (5.9 and 6.1 h) with GnRH treatment. There was also no effect of the pre-exposure to P4, type of inducer or interaction on the amplitude of the LH peak. We concluded that EB therefore led to greater LH release than GnRH, and pre-exposure to P4 before EB administration anticipated the preovulatory-like LH surge in buffalo cows.