Table 1.

Analysis of circulating growth hormone profiles in female rats serving as their own controls and subsequently treated with one dose of octreotide followed by ten additional doses.

	Number of Doses	Mean Concentration (ng/ml)	Peak Interval (min)	Pulse			Valley
Group				Width (min)	Height (ng/ml)	Area (μg.min.ml−1)	Width (min)	Nadir (ng/ml)
Control	-	54.8± 7.0	81.1± 10.5	58.9± 7.5	125.7± 36.2	3.74± 0.62	28.0± 4.6	27.6± 5.7
Octreotide	1	48.1± 8.1	76.2± 9.4	49.3± 9.1	131.0± 29.7	3.13± 0.58	32.0± 2.8	19.9± 5.4*
Octreotide	11	41.2± 4.6**	69.2± 7.1*	45.2± 4.8**	118.8± 22.4	2.73± 0.45**	33.1± 2.6*	17.0± 4.4**

Values are means ± S.D. with n=7.

^*P<0.05

^**P<0.01 compared to Control treatment.

Every rat was fitted with a chronic indwelling right atrial catheter for serial blood sampling (Pampori et al., 1991). Four to 5 days following catheter placement, serial blood samples were collected over 8 consecutive hours at 15 min intervals. Four to 5 days later, every rat was injected, iv, with 25μg octreotide/kg body weight and 5 min later, serial blood samples were again collected. Next, the rats were injected, iv, every 12 hr with the same dose of octreotide for a total of 11 doses. Five min following the last injection, serial blood collections were again obtained for 8 hr. Data were analyzed with the aid of the Cluster analysis program for hormonal pulse detection (Veldhuis and Johnson, 1986) according to peak interval, time period between peaks; width, duration of growth hormone pulses or interpulse valleys; height, amplitude of hormone peaks; area, integrated area under growth hormone pulses (concentration × duration); nadir, mean baseline growth hormone concentration. Mean concentration was calculated for the entire 8 hr collection period.