Nitroblut Tetrazolium Reduction of Neutrophils in Heat Stressed Goats Is Not Influenced by Selenium and Vitamin E Injection.

Abstract

ABSTRACT. Experiment was designed to determine whether heat stress suppresses neutrophil function and injections of selenium and vitamin E prior to heat stress prevent suppression of neutrophil function in goats. Twelve female goats were divided into 2 groups of 6 each and were kept at 25°C. Goats in the treatment group were injected intramuscularly with 0.1 mg/kg of selenium and 2.72 IU/kg of vitamin E at 8 and 1 day prior to the initiation of heat stress. The other group was kept as control. All goats were exposed to hot environment at 38°C from day 0 through 8. Decreased tendency in plasma cortisol concentrations and temporary increase in plasma glucose concentrations were shown in both groups. In the control group, plasma selenium concentration gradually increased and α-tocopherol concentration decreased during the first 2 days. After the second injection with selenium and vitamin E, plasma selenium and α-tocopherol concentrations significantly increased and remained higher than those in the control group. Whole blood glutathione peroxidase (GSH-Px) activity in the treatment group tended to be greater than that in the control group, but no significant difference was observed between 2 groups. The nitroblue tetrazolium (NBT) reduction by activated neutrophils significantly decreased on day 6 in the control group but not in the treatment group. The NBT reduction by resting neutrophils significantly decreased in both groups. These data suggest that heat stress depresses neutrophil function, and selenium and vitamin E injection prior to heat stress has no apparent effect on neutrophil function during the stress. -KEY WORDS: heat stressed goat, neutrophil, nitroblue tetrazolium reduction, selenium, vitamin E.

Clinical, haematological and biochemical findings in Saanen goat kids with naturally occurring heat stroke

“…In the present study the plasma lactate level was significantly higher in pre-treatment group when compared to the control group. A negative correlation between increased plasma lactate and decreased survival rate has been reported (22,28). Similarly, the two kids in the present study which died had higher plasma lactate levels than the surviving animals.…”

“…Heat production and respiratory evaporative heat loss have been presented as functions of three variables, i. e. hypothalamus temperature, spinal cord temperature and air temperature (25). Physiological thermolytic pathways under heat stress incorporate an increase in respiratory and cutaneous evaporative cooling (28), an increase in peripheral to splanchnic blood flow ratio have been implicated in goats (40,41) and the suppression of thermogenic hormone production (6). Low humidity and air movements are important to allow evaporation of sweat and convection of heat (2,14,15,17,25).…”

Effects of Night Grazing, Watering Regime, Time of the Day and Season on Respiration Rate and Rectal Temperature of Sudan Desert Sheep Ewes.

“…The rise in RR and RT with time of the day (Table3.) up to noon (12:00 hrs) and declining thereafter till the evening (18:00 hrs) was in conformity with increased respiration frequency following heat stress reported in goats (Katamoto et al, 1998), sheep (Gadberry et al, 2003) and cattle (Gaughan et al, 1999). Gaughan (2002) stated that a decreasing RR with rising ambient temperature is not always indicative of an animal coping with the hot conditions, but may indicate a failure to cope.…”

Perfil proteico e metabolismo oxidativo de cordeiros experimentalmente infectados pelo Haemonchus contortus e suplementados com selênio e vitamina E

“…A GSH-Px aumenta na circulação sanguínea em decorrência da maior disponibilidade de selênio sanguíneo, visto que é uma enzima dependente desse mineral (ROOKE et al, 2004;HALLIWELL & GUTTERRIDGE, 2007). KATAMOTO et al (1998) observaram uma tendência de maior atividade da GSHPx com a suplementação injetável de selênio e vitamina E, nas doses de: 0,1mg kg -1 e 2,72UI kg -1 , respectivamente, em cabras sob estresse térmico. No entanto, TAULER et al (2002) avaliaram a suplementação via oral de vitamina E, na dose de 500mg/dia, associada a outros agentes antioxidantes (vitamina C e beta-caroteno) na dieta de atletas, verificando um aumento de 47% da atividade da GSHPx no grupo tratado.…”