Do the pineal gland and melatonin play a role in diabetes mellitus type 1?

Do the pineal gland and melatonin play a role in diabetes mellitus type 1?

SOMATOSENSORY EVOKED POTENTIALS IN EXPERIMENTAL DIABETES I M. Bjegovi~ , V. I~gum 2 and M. Slijep~evi63 1,3 Department of Experimental Biology and Med...

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SOMATOSENSORY EVOKED POTENTIALS IN EXPERIMENTAL DIABETES I M. Bjegovi~ , V. I~gum 2 and M. Slijep~evi63 1,3 Department of Experimental Biology and Medicine, Rugjer Bo~kovi6 Institute, Zagreb, Croatia 2 Department of Neurology, Clinical Hospital Center~ Zagreb, Croatia

EFFECTS OF HEMIDESMUS INDICU$ ROOT EXTRACT ON SERUM GLUCOSE LEVELS OF NORMAL AND DIABETIC MODEL RATS

N.S. Chowdhury1, L Ali1, A,K. Azad Khan1, M Mosihuzzamanz, N. Nahar2, B. Rokeya1, M. Nur-e-Alam~ 1BIRDEM, 122 Kazi Nazrul Islam Avenue, Dhaka-1000and 2Deptof Chemist'y, University of Dhaka, Dhaka, Bangladesh

We studied the effect of chronic hyperglycemia, induced by single dose of alloxan monohydrate (65-75 mg/kg ±.v) on the somatosensory evoked potentials (SEPs) in rodents (rats, mice) of different age and sex, as compared to healthy animals. Special program for recording and analysis of SEPs was constructed and adapted to specific demands for recording of SEP s in small animals. SEPs obtained after electrical stimulation of the contralateralforepaw and recorded from thescalp of transiently anaesthetized animals, by an non invasive method, showed high reproducibility. In healthy mice the averaged SEPs represent the complex wave form characterized by defined latency peaks (N9, P14, N19, P22 and N27). Corresponding latency peaks were detected in rats of different age and sex (NIO, P17, N20, P22-24 and N25-N28). Experimental diabetes first two months after alloxan injection induced significant alteration of SEPs in both sepcies. Prolongation of interpeak latencies (177.6 to 189.2 %) seen in diabetic mice was accompanied by the marked rise of amplitude (N9, N19). Late components of latencies and ampl±tudes were reduced. Amplitude decrease occurTed in diabetic female rats of different ages. Delayed latency (137.6 %) appeared in 6 months elf female suffering diabetes for two months. Fast development of SEP changes might be attributed to rapid alteration in the CNS environment as an early consequence of beta-cell cytotoxin alloxan action on diabetes in rodents.

Hemidesmus indicus is used by the traditional practitioners in Bangladesh and India as an antidiabetic agent. Following a standardized experimental approach to investigate the hypoglycemic effect as well as the possible mechanism of action of plant materials, we have tested the alcohol extract of H indicus roots on nondiabeticand diabetic model rats. Freeze-dried extracts (250 rag) were fed to nondiabetic and diabetic (IDDM and NIDDM) model Long-Evans rats in various prandial states (fasting, 30 rain before and simultaneously with glucose load). In both nondiabetic and diabetic model rats no blood glucose lowering effec~twas observed when the extract was fed in the fasting state or 30 min before glucose load. However, in all the models blood glucose level was significantly loweredwhen the extractwas fed simultaneouslywith glucose (p<0.01- 0.001). In NIDDM model rats, a paradoxical increase of blood glucosewas observedin the fasting state (p<0.007). The resultssuggest that alcohol extract of H indicus root possess a hypoglycemicproperties which is probably mediated by delaying the absorption of glucose - an effect compatible with action of soluble dietary fibres. The results also indicate that folkloric reputationshould be regardedwith caution since an extract may rather lead to harmful consequencesat a particular prandial state.

DO THE PINEAL GLAND AND MELATONIN PLAY A ROLE IN DIABETES MELLITUS TYPE I ? ARIO CONTI a n d GEORGES J.M. MAESTRONI Centre for Experimental Pathology, Istituto Cantonale di Patologia, 6604 Locarno Switzerland.

E F F E C T S O F INSULIN, INSULIN-SULFONUREA AND S U L F O N U R E A T R E A T M E N T IN OBESE AND NON OBESE TYPE H DIABETICS. M.Dworacka, K. Szczawifiska. Department of Pharmacology, K.Marcinkowski University of Medical Sciences,Po~aan,Poland.

We h a v e d e m o n s t r a t e d that the pineal g l a n d a n d melatonin (MLT) play an immunoregulatory role both in mice and in humans. In particular : a) MLT enhances the primary a n t i b o d y response in n o r m a l a n d stressed animals; b ) counteracts t h e immunosuppressive e f f e c t i n d u c e d by a c u t e stress a n d / o r by corticosteroid t r e a t m e n t a n d ¢) exerts these interesting effects triggering the synthesis a n d / o r release of o p i o i d p e p t i d e from a c t i v a t e d CD4 +, T lymphocytes. Furthermore MLT acts on T helper lymphocytes inducing the release of IL-4. These findings p r o m p t e d us to investigate the role of the pineal g l a n d a n d MLT in diabetes mellitus tipe I. The NOD mouse has b e e n used as e x p e r i m e n t a l model. Preliminary results shows that in female NOD mouse: 1) n e o n a t h a l pinealectoy accelerate the d e v e l o p m e n t of t h e disease; 2) e x o g e n o u s MLT increase the production of IAA as expected. Further studies are in prgress in our laboratory to asses t h e role o f t h e pineal g l a n d a n d MLT in t h e i m m u n o p a t h o g e n e s i s of diabetes mellitus t y p e I.

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Obesity is frequent concomitant disturbance in patients with type I/ diabetes (NIDDM). The pathogenesis of NIDDM in the case of accompanying obesity probably differs from that in non obese type II diabetics (1,2). Also, there is an unresolved problem, if the effects of routine hypoglycemie therapy differs between this groups, as well 109 obese and 30 non obese, type 1I diabetics treated with insulin (55 obese and 10 non obese), gliclazide (29 obese and 10 non obese) or with insulin-gliclazide combination (25 obese and 10 non obese) were examined. Basic medical examination was done and several parameters of metabolic control (O~ting glycemia, glycated hemoglobin HbAle, triglycerides, total cholesterol) were determined. We observed, that in group treated with insulin-glielazide combination or with insulin only, plasma concentration of triglycerides was higher in obese diabetics. In glicla~de treated group, obese patients were characterised by significantly higher values of fasting glycemia, HbAle and triglycerides. In summary: it could be suggested that, gliclazide therapy is significantly less effective in obese, type II diabetics. 1.Amer P. :Different etiologies of Type 2 (non-insulin-dependent) diabetes meUitus in obese and non obese subjects. Diabetologia, 1991, 34, 483. 2.Tatoti J. :Real and apparent associations between obesity and noninsulin-dependent diabetes mellitus and some other disturbances: therapeutic conclusions. Polski Tygodnik Lekarski 1993, supl. 1, 45.

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