Luna S P, Taylor P M, Bloomfield M
Animal Health Trust, Newmarket, United Kingdom.
Am J Vet Res. 1997 Jul;58(7):765-70.
To investigate the effects of inhalation and total IV anesthesia on pituitary-adrenal activity in ponies.
9 healthy ponies: 5 geldings and 4 mares.
Catheters were placed in the cavernous sinus below the pituitary gland and in the subarachnoid space via the lumbosacral space. After 72 hours, administration of acepromazine was followed by induction of anesthesia with thiopentone and maintenance with halothane (halothane protocol), or for the IV protocol, anesthesia induction with detomidine and ketamine was followed by maintenance with IV infusion of a detomidine-ketamine-guaifenesin combination. Arterial blood pressure and gas tensions were measured throughout anesthesia. Peptide and catecholamine concentrations were measured in pituitary effluent, peripheral plasma, and CSF. Peripheral plasma cortisol, glucose, and lactate concentrations also were measured.
Intravenous anesthesia caused less cardiorespiratory depression than did halothane. ACTH, metenkephalin, arginine vasopressin, and norepinephrine pituitary effluent and peripheral plasma concentrations were higher during halothane anesthesia, with little change during intravenous anesthesia. Pituitary effluent plasma beta-endorphin and peripheral plasma cortisol concentrations increased during halothane anesthesia only. Dynorphin concentrations did not change in either group. Hyperglycemia developed during intravenous anesthesia only. Minimal changes occurred in CSF hormonal concentrations during anesthesia.
The pituitary gland has a major role in maintaining circulating peptides during anesthesia. Compared with halothane, IV anesthesia appeared to suppress pituitary secretion.
研究吸入麻醉和全静脉麻醉对小马垂体 - 肾上腺活性的影响。
9匹健康小马，5匹阉马和4匹母马。
将导管置于垂体下方的海绵窦以及经腰骶间隙置于蛛网膜下腔。72小时后，先给予乙酰丙嗪，然后用硫喷妥钠诱导麻醉并用氟烷维持（氟烷方案）；或者对于静脉麻醉方案，先用右美托咪定和氯胺酮诱导麻醉，然后用右美托咪定 - 氯胺酮 - 愈创甘油醚混合液静脉输注维持。在整个麻醉过程中测量动脉血压和血气张力。测量垂体流出液、外周血浆和脑脊液中的肽和儿茶酚胺浓度。还测量外周血浆皮质醇、葡萄糖和乳酸浓度。
静脉麻醉引起的心肺抑制比氟烷少。在氟烷麻醉期间，促肾上腺皮质激素、甲硫脑啡肽、精氨酸加压素和去甲肾上腺素在垂体流出液和外周血浆中的浓度较高，而在静脉麻醉期间变化不大。垂体流出液中的血浆β - 内啡肽和外周血浆皮质醇浓度仅在氟烷麻醉期间升高。两组中的强啡肽浓度均无变化。仅在静脉麻醉期间出现高血糖。麻醉期间脑脊液激素浓度变化极小。
垂体在麻醉期间维持循环肽方面起主要作用。与氟烷相比，静脉麻醉似乎抑制垂体分泌。
