RESUMEN
We aimed to evaluate the effects of rumen-protected lysine (RPL) supplementation during the close-up period on uterine involution and the resumption of ovarian function in dairy cows. Fifty-two multiparous Holstein cows were categorized based on parity and expected calving date and randomly assigned to the RPL or control (CON) groups. The RPL group received 80 g of RPL daily from day 21 before the expected calving date until parturition. Blood samples were obtained twice weekly from pre-supplementation to 6 weeks postpartum. The onset of luteal activity postpartum was determined via ultrasonography twice weekly for up to 6 weeks postpartum. Uterine involution was tracked at 3 and 5 weeks postpartum through the vaginal discharge score, percentage of polymorphonuclear cells (PMN) in endometrial cytology samples, presence of intrauterine fluid, and gravid horn diameter via ultrasonography. Before supplementation, the RPL group showed amino acid imbalance, which was improved by RPL supplementation. There were no significant differences in the onset of luteal activity, percentage of PMN, intrauterine fluid, or the diameter of the uterine horn between the two groups. The vaginal discharge score in the RPL group decreased from 3 to 5 weeks postpartum, whereas that in the CON groups did not decrease. The number of cows with clinical endometritis was lower in the RPL group. Overall, RPL supplementation during the close-up period enhanced vaginal discharge clearance, potentially averting clinical endometritis, but did not affect the first ovulation in dairy cows.
Asunto(s)
Enfermedades de los Bovinos , Endometritis , Excreción Vaginal , Animales , Bovinos , Femenino , Embarazo , Enfermedades de los Bovinos/tratamiento farmacológico , Enfermedades de los Bovinos/prevención & control , Enfermedades de los Bovinos/metabolismo , Dieta/veterinaria , Suplementos Dietéticos , Endometritis/prevención & control , Endometritis/veterinaria , Endometritis/metabolismo , Lactancia , Luteína/análisis , Luteína/metabolismo , Lisina/farmacología , Leche/química , Periodo Posparto , Rumen/metabolismo , Excreción Vaginal/veterinariaRESUMEN
Thermogenesis in the brown adipose tissue (BAT) is activated by the stimulation of the ventromedial hypothalamic nucleus (VMH). Local warming of the preoptic area (PO) suppresses this response. Injection of the GABA(A) receptor antagonist bicuculline into the caudal periaqueductal gray (cPAG), where excitatory neurons for BAT thermogenesis are located, did not influence the suppressive effect of PO warming. On the other hand, after bicuculline injection into the raphé pallidus, where excitatory neurons for BAT thermogenesis are also located, VMH stimulation produced BAT thermogenesis even during PO warming. The present results suggest that the inhibitory signal from the PO reaches the raphé pallidus and not the cPAG for the control of BAT thermogenesis.
Asunto(s)
Temperatura Corporal/fisiología , Área Preóptica/fisiología , Núcleos del Rafe/fisiología , Termogénesis/fisiología , Núcleo Hipotalámico Ventromedial/fisiología , Tejido Adiposo Pardo/efectos de los fármacos , Tejido Adiposo Pardo/fisiología , Animales , Bicuculina/farmacología , Temperatura Corporal/efectos de los fármacos , Estimulación Eléctrica/métodos , Masculino , Inhibición Neural/efectos de los fármacos , Inhibición Neural/fisiología , Vías Nerviosas/efectos de los fármacos , Vías Nerviosas/fisiología , Área Preóptica/efectos de los fármacos , Núcleos del Rafe/efectos de los fármacos , Ratas , Ratas Wistar , Tiritona/efectos de los fármacos , Tiritona/fisiología , Termogénesis/efectos de los fármacos , Núcleo Hipotalámico Ventromedial/efectos de los fármacosRESUMEN
To investigate the involvement of the periaqueductal gray (PAG) in the control of non-shivering thermogenesis, we tested the effects of electrical or chemical stimulation of the PAG on thermogenesis of brown adipose tissue (BAT) in urethane anesthetized rats. Electrical stimulation (0.1 mA, 33 Hz, 0.5 ms) or application of D,L-homocysteic acid (0.5 mM, 0.3 micro l) into the lateral region of the caudal PAG (cPAG) elicited BAT thermogenesis, measured as a rise in the local temperature of interscapular BAT. These results suggest that neurons in the cPAG send excitatory efferent signals for BAT thermogenesis.
Asunto(s)
Tejido Adiposo Pardo/fisiología , Homocisteína/análogos & derivados , Sustancia Gris Periacueductal/fisiología , Termogénesis/fisiología , Tejido Adiposo Pardo/efectos de los fármacos , Animales , Estimulación Eléctrica , Homocisteína/administración & dosificación , Homocisteína/farmacología , Inyecciones Intraventriculares , Masculino , Vías Nerviosas , RatasRESUMEN
We examined body core and skin temperatures and thermal comfort in young Japanese women suffering from unusual coldness (C, n = 6). They were selected by interview asking whether they often felt severe coldness even in an air-conditioned environment (20-26 degrees C) and compared with women not suffering from coldness (N, n = 6). Experiments were conducted twice for each subject: 120-min exposure at 23.5 degrees C or 29.5 degrees C after a 40-min baseline at 29.5 degrees C. Mean skin temperature decreased (P < 0.05) from 33.6 +/- 0.1 degrees C (mean +/- SE) to 31.1 +/- 0.1 degrees C and from 33.5 +/- 0.1 degrees C to 31.1 +/- 0.1 degrees C in C and N during the 23.5 degrees C exposure. Fingertip temperature in C decreased more than in N (P < 0.05; from 35.2 +/- 0.1 degrees C to 23.6 +/- 0.2 degrees C and from 35.5 +/- 0.1 degrees C to 25.6 +/- 0.6 degrees C). Those temperatures during the 29.5 degrees C exposure remained at the baseline levels. Rectal temperature during the 23.5 degrees C exposure was maintained at the baseline level in both groups (from 36.9 +/- 0.2 degrees C to 36.8 +/- 0.1 degrees C and 37.1 +/- 0.1 degrees C to 37.0 +/- 0.1 degrees C in C and N). The rating scores of cold discomfort for both the body and extremities were greater (P < 0.05) in C than in N. Thus the augmented thermal sensitivity of the body to cold and activated vasoconstriction of the extremities during cold exposure could be the mechanism for the severe coldness felt in C.