EVALUATION OF ANTI-HYPERTENSIVE ACTIVITY OF TEST FORMULATIONS IN RAT MODEL OF ONE KIDNEY ONE CLIP (1K1C) HYPERTENSION

  EVALUATION OF ANTIHYPERTENSIVE ACTIVITY OF TEST FORMULATIONS IN RAT MODEL OF ONE KIDNEY ONE CLIP (1K1C) HYPERTENSION

TEST SYSTEM DETAILS:

Species : Rattus norvegicus (Rats)

Strain : Sprague Dawley or Wistar

Age : 6-7 weeks

Sex : Male

No. of animals : 8 /Group

Total animals : 48

1.0   ALLOCATION OF GROUPS:

 

Group No.	Group Description	Disease-Induction agent administered	Treatment administered	Dose Volume and Route
G1	Normal Control	Animals will be anesthetized with 50 mg/kg i.p Thiopentone and the fur on the back will be shaved and the skin disinfected.	0.5% MC, p.o., b.i.d.	5 ml/kg, p.o.
G2	Disease Control	The renal artery will be traced out and a U-shaped silver clip will be clipped around it near the aorta, The right kidney will be removed after tying the renal pedicle.	0.5% MC, p.o., b.i.d
G3	Reference Control (Captopril)		50 mg, 0.5% MC, p.o., q.d.
G4	Treated with a low dose of TC-1		TC-1-X1 mg/kg, b.i.d.  in 0.5% MC
G5	Treated with intermediate dose 1 of TC-2		TC-2-X2 mg/kg,    b.i.d. in 0.5% MC
G6	Treated with intermediate dose 2 of TC-3		TC-3-X3 mg/kg,   b.i.d. in 0.5% MC

Abbreviations: per os. q.d.: quaque die; bid: bis in die. X1, X2, and X3 are defined as the incremental doses of the Test formulations. The dose range will be from 10 mg/kg to 1000 mg/kg, b.i.d.

2.0  METHOD:

Healthy animals will be selected for the study, randomized based on body weight, and will be assigned to 11 groups consisting of 8 animals each.

· Animals of Group G1 will be designated as normal-control and treated with vehicle 0.5% MC, p.o, b.i.d.

· Disease control animals (assigned to group G2) will be treated with vehicle 0.5% MC, p.o., b.i.d.

· Animals of group G3 will be treated with Captopril 50 mg, 0.5% MC, p.o., q.d.at the (in the morning).

· Animals of group G4-G6 will be treated with TC-1, at different dose levels ranging from 10-1000 mg/kg, b.i.d.

· Normal control group (G1) will be treated vehicle 0.5% MC, p.o, b.i.d., whereas animals allocated to groups G2-G6 will be treated with Test formulations.

· Compound administration will be initiated from day 43-56, after confirmation of hypertension above 150 mm hg in G2-G6 groups.

· On day 0, before the initiation of the experiment, animals will be anesthetized with 50 mg/kg i.p Thiopentone and the fur on the back will be shaved and the skin disinfected. In the left lumbar area of the flank, an incision will be made parallel to a long axis of the rat. The renal pedicel will be exposed with the kidney retracted to the abdomen. The renal artery will be traced out and a U-shaped silver clip will be clipped around it near the aorta. Using special forceps, the size of the clip will be adjusted so that the internal gap ranges from 0.25-0.38 mm. The right kidney will be removed after tying the renal pedicle. The skin incisions will be closed and appropriate treatment will be given to prevent infection to the wounds. 4-5 weeks after clipping blood pressure will be measured and rats with values higher than 150 mmHg selected for the experiments. Blood pressure readings will be taken on each of the 3 days prior to drug treatment. Subsequently, after week eight on day 57, all animals will be sacrificed under an overdose of thiopentone anesthesia. After suitable anesthesia but before the animal dies, blood will be collected from the retro-orbital plexus for the estimation of hematological parameters. Immediately after the animal dies, the heart, kidneys, and aorta will be collected and will be fixed in 10% neutral buffered formalin for histopathological whereas some parts of the organ and one organ among from pair of organs will be stored at -80°C for the ensuing biochemical and molecular evaluations.

 

3.0  PARAMETERS TO BE EVALUATED:

·        Body weight: Twice a week.

·    Tail-Cuff Method Blood Pressure Measurement (On Weeks -5, 7, and 8, Six readings will be taken and the average of six will be taken as individual systolic blood pressure)

·        Biochemical parameters: ACE Inhibitory Activity will be measured

·        Histological analysis of the Heart, Kidney, and Aorta.

 

4.0  REFERENCE(S):

1. Brunton LL, Lazo JS, Parker KL. Goodman and Gilman’s The Pharmacological Basis of Therapeutics. 11th ed. New York: McGraw Hill 2006: p. 845-6.

2. Li GH, Qu MR. Wan JZ, You JM. Antihypertensive effect of rice protein hydrolysate with in vitro angiotensin I converting enzyme inhibitory activity in spontaneously hypertensive rats. Asia Pac J Clin Nutr 2007;16(1):275-80.

3. Lopez FR, Otte J, Camp V. Physiological, chemical and technological aspects of milk-protein-derived peptides with antihypertensive and ACE-inhibitory activity. Int Dairy J 2006;16:1277-93.

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