title: Substrate concentration changes during pregnancy in the guinea pig studied under unstressed steady state conditions.
abstract: Weight gain and food intake were measured in unstressed nonpregnant and pregnant guinea pigs fed ad libitum. Nonpregnant females consumed 33.2 +/- 0.5 g.day-1 of pellet diet and did not demonstrate a consistent pattern of weight gain. The average daily food intake of pregnant animals increased linearly from 38 g.day-1 at 27 days to over 60 g.day-1 near term, and the average maternal weight gain was 13.3 g.day-1. Using sterile technique, polyvinyl catheters were inserted under anesthesia into the carotid and femoral arteries of these animals. Animals recovered spontaneously, and catheters remained patent for up to 4 wk. The effect of surgical and anesthetic stress was evaluated by measurement of food intake and metabolite levels after surgery. In the nonpregnant animals, blood glucose decreased immediately after surgery (4.76 +/0- 0.36 versus 5.65 +/- 0.25; P less than 0.05), whereas the pregnant animals responded with a substantial increase in blood glucose (7.57 +/- 0.48 versus 5.87 +/- 0.33; P less than 0.05). Lactate was increased intraoperatively in both groups (1.76 +/- 0.22 versus 1.11 +/- 0.07, nonpregnant; 1.80 +/- 0.17 versus 1.10 +/- 0.08, pregnant). The pregnant animals differed from the nonpregnant animals with regard to the pattern of changes in blood ketones after surgery. The nonpregnant animals achieved steady state within 1 day after surgery, whereas the pregnant animals required 4 days for recovery. Food intake and maternal weight gain were markedly reduced during the recovery period for the pregnant animals. Blood metabolite levels were measured in well-fed, unstressed pregnant and nonpregnant guinea pigs. Using measurements made after the third postoperative day, the unstressed pregnant animals demonstrated a progressive decline in blood glucose levels, reaching levels significantly below those of nonpregnant animals at 55 to 60 and 60+ days. Arterial concentrations of lactate, pyruvate, beta-hydroxybutyrate, acetoacetate, and free fatty acids did not change consistently with gestation and were not significantly different from nonpregnant values.
mesh_terms: D020155:3-Hydroxybutyric Acid; D000090:Acetoacetates; D000818:Animals; D001786:Blood Glucose / Q000032:analysis*; D001835:Body Weight; D005230:Fatty Acids, Nonesterified / Q000097:blood*; D005260:Female; D006168:Guinea Pigs; D006885:Hydroxybutyrates / Q000097:blood; D007651:Keto Acids / Q000097:blood; D007659:Ketones / Q000097:blood*; D007773:Lactates / Q000097:blood*; D011247:Pregnancy; D011248:Pregnancy Complications / Q000097:blood; D011270:Pregnancy, Animal; D011773:Pyruvates / Q000097:blood; D013312:Stress, Physiological / Q000097:blood / Q000209:etiology
chemical_list: D000090:Acetoacetates; D001786:Blood Glucose; D005230:Fatty Acids, Nonesterified; D006885:Hydroxybutyrates; D007651:Keto Acids; D007659:Ketones; D007773:Lactates; D011773:Pyruvates; C016635:acetoacetic acid; D020155:3-Hydroxybutyric Acid