Alterations of Hormone-Sensitive Adenylyl Cyclase System in the Tissues of Rats with Long-Term Streptozotocin Diabetes and the Influence of Intranasal Insulin

Table 5

The inhibitory effects of hormones on forskolin-stimulated AC activity in the tissues of diabetic and control rats with and without I-I treatment. C: control animals; CI: control animals treated with intranasal insulin (I-I); D: diabetic animals with 210-day streptozotocin-induced diabetes mellitus of the type 1 (T1DM); DI: diabetic animals treated with I-I. The stimulating effect of forskolin (10⁻⁵ M) on the basal AC activity is taken as 100%. Values are the weighted mean ± weighted standard deviation of three individual experiments, each performed in triplicate.

(a) In percentages

	Group C	Group CI	Group D	Group DI
	Heart
Somatostatin	52 ± 3%; (C-D, P = 10^−8; C-CI, P = 0.7090)	55 ± 2%; (CI-DI, P = 10^−7)	88 ± 3%; (D-DI, P = 0.0070)	78 ± 3%
Average of the first series	51	55	90	77
Average of the second series	59	57	83	83
Average of the third series	50	45	87	73
Noradrenaline	44 ± 2%; (C-D, P = 10^−6; C-CI, P = 0.0927)	49 ± 2%; (CI-DI, P = 0.4005)	73 ± 3%; (D-DI, P = 0.00015)	49 ± 4%
Average of the first series	44	51	63	52
Average of the second series	43	48	78	56
Average of the third series	42	42	69	43
	Brain
Somatostatin	50 ± 3%; (C-D, P = 0.0006; C-CI, P = 0.1043)	47 ± 3%; (CI-DI, P = 0.0032)	66 ± 4%; (D-DI, P = 0.0745)	58 ± 4%
Average of the first series	47	44	76	50
Average of the second series	52	52	62	67
Average of the third series	53	41	65	60
Noradrenaline	80 ± 3%; (C-D, P = 0.1763; C-CI, P = 0.6663)	87 ± 3%; (CI-DI, P = 0.9149)	93 ± 3%; (D-DI, P = 0.4016)	84 ± 3%
Average of the first series	80	79	96	78
Average of the second series	92	86	84	84
Average of the third series	78	91	88	95
Bromocriptine	72 ± 3%; (C-D, P = 0.0276; C-CI, P = 0.7451)	71 ± 4%; (CI-DI, P = 0.1306)	81 ± 3%; (D-DI, P = 0.4622)	81 ± 2%
Average of the first series	65	64	92	84
Average of the second series	68	76	74	78
Average of the third series	81	79	79	74
5-Nonyloxytryptamine	67 ± 4%; (C-D, P = 10^−6; C-CI, P = 0.2520)	62 ± 5%; (CI-DI, P = 0.0446)	93 ± 3%; (D-DI, P = 10^−5)	70 ± 3%
Average of the first series	66	59	90	79
Average of the second series	63	66	91	68
Average of the third series	73	64	95	67
	Testes
Somatostatin	64 ± 3%; (C-D, P = 10^−7; C-CI, P = 0.3465)	67 ± 4%; (CI-DI, P = 10^−6)	95 ± 3%; (D-DI, P = 0.7882)	93 ± 3%
Average of the first series	65	73	104	107
Average of the second series	60	67	91	89
Average of the third series	64	59	96	93

(b) In picomole (pmol) of cAMP/min per milligram (mg) of membrane protein

	Group C	Group CI	Group D	Group DI
	Heart
Somatostatin	105.2 ± 5.7; (C-D, P = 0.0039; C-CI, P = 0.8304)	111.8 ± 3.8; (CI-DI, P = 0.0011)	127.2 ± 4.1; (D-DI, P = 0.4273)	129.0 ± 5.1
Average of the first series	102.5	111.0	130.5	128.4
Average of the second series	119.3	115.0	119.9	137.8
Average of the third series	99.8	91.4	126.6	121.7
Noradrenaline	87.6 ± 4.1; (C-D, P = 0.0080; C-CI, P = 0.0666)	99.7 ± 4.2; (CI-DI, P = 0.0596)	105.4 ± 4.5; (D-DI, P = 0.0110)	81.8 ± 6.6
Average of the first series	88.4	104.2	91.8	86.9
Average of the second series	87.1	98.1	112.6	93.0
Average of the third series	84.4	85.9	105.1	70.8
	Brain
Somatostatin	82.8 ± 4.7; (C-D, P = 0.0064; C-CI, P = 0.0721)	76.9 ± 5.0; (CI-DI, P = 0.0203)	100.4 ± 5.8; (D-DI, P = 0.0882)	89.4 ± 5.4
Average of the first series	78.6	71.6	115.5	76.5
Average of the second series	86.3	85.3	94.2	102.5
Average of the third series	87.4	67.8	98.8	92.3
Noradrenaline	132.4 ± 5.3; (C-D, P = 0.6643; C-CI, P = 0.8534)	142.5 ± 5.5; (CI-DI, P = 0.1950)	140.8 ± 4.4; (D-DI, P = 0.4807)	128.7 ± 4.7
Average of the first series	133.4	129.6	145.9	119.3
Average of the second series	153.3	141.6	127.7	128.5
Average of the third series	129.5	148.7	133.8	145.9
Bromocriptine	120.3 ± 5.5; (C-D, P = 0.4123; C-CI, P = 0.8973)	116.1 ± 7.0; (CI-DI, P = 0.8306)	122.6 ± 4.0; (D-DI, P = 0.5505)	124.6 ± 2.9
Average of the first series	108.5	105.0	139.8	129.0
Average of the second series	112.9	124.1	112.5	119.9
Average of the third series	134.5	129.6	120.6	113.7
5-Nonyloxytryptamine	111.7 ± 6.8; (C-D, P = 0.000006; C-CI, P = 0.1797)	102.2 ± 8.1; (CI-DI, P = 0.3600)	140.9 ± 3.9; (D-DI, P = 10^−5)	107.7 ± 4.9
Average of the first series	109.6	97.3	136.8	120.9
Average of the second series	105.1	108.2	138.8	104.0
Average of the third series	121.2	104.4	144.4	102.0
	Testes
Somatostatin	26.3 ± 1.0; (C-D, P = 10^−7; C-CI, P = 0.6490)	25.6 ± 1.5; (CI-DI, P = 10^−4)	17.1 ± 0.6; (D-DI, P = 0.0354)	21.5 ± 0.6
Average of the first series	26.8	27.9	18.8	24.5
Average of the second series	24.6	25.5	16.4	20.4
Average of the third series	26.2	22.4	17.3	21.4