ABSTRACT
Dexamethasone is widely used in both veterinary and human medical practices. However, it seems to cause some deleterious effects on pregnancy probably by causing changes in the reproductive hormone levels and their corresponding receptor concentrations. This study investigated the effects of dexamethasone on these parameters. Twenty healthy adult Yankasa sheep comprising 18 ewes and 2 rams were used for this study. Pregnancies were achieved by natural mating after estrus synchronization. Dexamethasone was administered at 0.25 mg/kg body weight on days 1, 3, and 5 during first trimester; days 51, 53, and 55 during second trimester; and days 101, 103, and 105 during the third trimester. Blood samples were collected biweekly for hormonal assay. Uterine biopsies were harvested through caesarean section for immunohistochemical analysis. Results showed that dexamethasone significantly (p < 0.05) decreased progesterone concentrations and caused abortion in Yankasa sheep but had no significant (p > 0.05) effect on estrogen, while progesterone receptors (PR) were upregulated. The abortion could probably be due to decreased progesterone concentrations as a consequence of the adverse effects on placenta. The PR upregulation may be a compensatory mechanism to increase progesterone sensitivity. It was concluded that dexamethasone should not be used in advanced pregnancy in Yankasa sheep.
ABSTRACT
BACKGROUND: Despite the widespread use of dexamethasone in veterinary and human medicine, it is reported to cause some severe pregnancy related side effects like abortion in some animals. The mechanism of the response is not clear but seems to be related to interspecies and/or breed difference in response which may involve alterations in the concentrations of some reproductive hormones. METHODS: Twenty Sahel goats comprising 18 does and 2 bucks were used for this study. Pregnancies were achieved by natural mating after synchronization. Repeated dexamethasone injections were given at 0.25 mg/kg body weight. Blood samples were collected biweekly for hormonal assay. Uterine biopsies were harvested at days 28 and day 78 of gestation through caesarean section for immunohistochemical analysis using 3 pregnant does randomly selected from each group at each instant. Data were expressed as Means ± Standard Deviations and analyzed using statistical soft ware package, GraphPad Instant, version 3.0 (2003) and progesterone receptor (PR) were scored semi-quantitatively. RESULTS: Dexamethasone treatments had no significant (p > 0.05) effect on progesterone and estrogen concentrations in pregnant Sahel goats but up regulated PR from 2+ to 3+ in second trimester. CONCLUSION: As dexamethasone adverse effect on placenta is an established fact, the lack of effect on progesterone level in this study may be due to the fact that unlike other species whose progesterone production during pregnancy is placenta - dependent, in goats is corpus luteum - dependent. Consequently dexamethasone adverse effect on placenta reported in literatures did not influence progesterone levels during pregnancy in Sahel goat. The up regulation of progesterone receptor (PR) in Sahel goat gravid uterus is a beneficial effects and that dexamethasone can safely be used in corpus luteum - dependent progesterone secreting pregnant animal species like Sahel goat and camel. Therefore source of progesterone secretions during pregnancy should be considered in clinical application of dexamethasone in pregnancy.
ABSTRACT
Background: Goat meat is very popular and has a great demand all over Nigeria. However, the slaughter of pregnant goats in abattoirs and slaughter slabs for meat is becoming a serious concern not only for future livestock population, but also for public health.Dyslipidaemia of pregnancy in meat animals may constitute threat to consumers in terms of cardiovascular risks. Objectives: The purpose of this study was to investigate the concentrations of serum lipids at different stages of gestation in Sahel goats and to evaluate the atherogenic capacity of the lipid profile. Materials and Methods: Serum lipids profiles and atherogenic indices in pregnant and nonpregnant Sahel goats were studied. Fourteen apparently healthy adult Sahel goats comprising 12 does with mean gestation length of 148.33 ± 1.52 days and 2 bucks were used for the study. They were managed in the University of Maiduguri livestock research farm on low fat diet. Sera samples were collected biweekly for 5 months and were used for the analysis of total Cholesterol (TC), triglycerides (TG), high density lipoprotein (HDL-c), low density lipoprotein (LDL-c) and very low density lipoprotein (VLDL-c). Atherogenic indices were calculated as base 10 log (TG/HDL-c). Results: Serum TG and VLDL-c concentrations increased significantly (p < 0.05) in pregnant does compared to non-pregnant. HDL-c and LDL-c concentrations did not vary significantly (p > 0.05) between the two groups. Atherogenic indices increased progressively with advancing pregnancy compared to non-pregnant. Conclusion: It was concluded that atherogenic capacity of the lipid profile in pregnant Sahel goats is high and therefore consumption of meat from pregnant animals has high potential for atherogenic risk. Routine antemortem inspection should be conducted at abattoirs to identify pregnant animals for restriction against slaughter. Legislation prohibiting the slaughter of pregnant animals should be enforced
