Effects of Melatonin on Adrenal Cortical Functions of Indian Goats under Thermal Stress

Abstract

The study was conducted with the primary objective to establish the influence of melatonin on adrenocortical functions to ameliorate thermal stress in goats. Endocrine secretions and several other blood biochemical parameters reflecting the animals adrenocortical stress response were determined over a one-week period after goats had been exposed to 40°C and 60%RH for 10 days. The study was conducted for a period of 17 days in psychrometric chamber. The animals served as self-controls prior to start of the experiment. Blood samples were drawn on day 10 to establish effect of thermal stress. Chemical adrenalectomy was achieved using metyrapone followed by exogenous melatonin treatment. 40°C of thermal stress which is quite normal in tropical zone significantly (P ≤ .05) influenced all parameters except plasma insulin. Metyrapone treatment significantly (P ≤ .05) affected plasma levels of glucose, total protein, total cholesterol, cortisol, and aldosterone. Metyrapone aggravated thermal stress by decreasing cortisol level in goats. Melatonin treatment at 11:00 AM significantly (P ≤ .05) influenced plasma levels of glucose, total protein, total cholesterol, cortisol, aldosterone and insulin. Metyrapone treatment aggravated thermal stress although administration of melatonin could ameliorate the condition. This establishes the role of melatonin in relieving thermal stress in goats.

Adaptive capability as indicated by endocrine and biochemical responses of Malpura ewes subjected to combined stresses (thermal and nutritional) in a semi-arid tropical environment

“…Plasma glucose decreased significantly in GII, GIII, and GIV ewes as compared to control ewes, with the greatest decrease being seen in the combined stress group. Several researchers have studied the effect of thermal stress on blood glucose concentrations but conflicting results have been reported (More and Sahni 1980;Habeeb 1987;Sejian and Srivastava 2010). The decrease in plasma glucose could also be due to the marked dilution of blood or increase in plasma glucose utilization to produce more energy for the greater muscular expenditure required for high muscular activity (Naqvi and Hooda 1991;Rasooli et al 2004).…”

Effects of Simultaneous Melatonin Administration on the Testis of the Experimentally Induced Hyper- and Hypothyroidism in the Adult Male Albino Rat

“…The light microscopic examination of the semithin sections of the testis of the hypothyroidic group (group 4) revealed seminiferous tubules with lumen devoid of spermatozoa and obliterated seminiferous tubules lumina with debris (Figs. 19,21). Additionally, some tubules were lined by disorganized germ cells with empty spaces in between the cells (Fig.…”

“…An oedematous interstitial tissue among the tubules revealing dilated blood vessel and shrunken darkly stained Leydig cells were observed (Figs. [19][20][21].…”

Pineal Proteins Upregulate Specific Antioxidant Defense Systems in the Brain

“…Our earlier findings also revealed that these buffalo PP and peptides have certain physiological functions viz. immunopotentiation,12 heat stress,13 amelioration of fluoride-induced OS and apoptosis 8,14. These proteins have a geroprotective effect which might be due to their free radical scavenging ability and thus antioxidant properties 15,16.…”