LOCAL INFUSION OF GLUCOSE AND INSULIN IN ISOLATED SKIN PERFUSION SITES IN ANGORA-GOATS

Six Angora goats (average BW 35.0 +/- 2 kg) were implanted bilaterally with silicon catheters in the superficial branch of the deep circumflex iliac artery and in the superficial branch of the deep circumflex iliac vein to determine the utilization of glucose and its insulin dependency in skin tissue. Intraarterial glucose infusion (Expt. 1 ) of 15 and 150 mg/h did not change glucose level in venous blood drained from that region. However, infusion of 750 mg/h of glucose increased venous blood glucose level by 87.9% (66.3 vs. 124.6 mg/dl; P < 0.01). Insulin concentration in venous blood from the treated side was significantly lower (11.3 vs, 12.9 muU/ml; P < 0.01) than in venous blood from the control side. Infusion of a constant dose of glucose (750 mg/h) (Expt. 2) in combination with a low level of insulin (100 muU/h) increased venous glucose relative to preinfusion level ( 1 06.8 vs. 62.3 mg/dl; P < 0.01 ). However, infusion of glucose with 1000 muU/h of insulin or 10 000 muU/h reduced (P < 0.01) the glucose level approximately to its initial value (84.2 and 69.4 mg/dl, respectively). Infusion of glucose alone or with insulin decreased (P < 0.01) nonesterified fatty acids concentration in the blood from 523 muEq/l in the baseline sample to 284 muEq/l. Blood flow in the explored region varied from 164 to 222 ml/min. This study demonstrates that infusion of low levels of hormones to local skin areas can be accomplished without affecting systemic hormone and metabolite profiles.