The Effect of Pentadecapeptide BPC 157 on Episcleral Vein Cauterization Model in Rats
Authors: Kralj Tamara , Kokot Antonio , Kasnik Katarina , Drmic Domagoj , Zlatar Mirna , Seiwerth Sven , Sikiric Predrag 
Published: November 2023

AimPreviously, in a short term study, stable gastric pentadecapeptide BPC 157 initially counteracts increased intraocular pressure (IOP) in rats underwent episcleral cauterization (The FASEB Journal, Vo. 30 No.1 supplement 1201.4). Now, in a six month study, rats underwent episcleral cauterization instead continuously exhibiting increased IOP, showed normal intraocular pressure with BPC 157 therapy, given daily, in the whole six month period.Materials and methodsMale Albino Wistar rats, 200g, anesthetized (Ketmine‐HCl 50–60mg/kg + Xylazine‐HCl 5–10mg/kg, Tetrakain 0.5% drops), randomly divided were used for surgery (two dorsal episcleral veins and one temporal episcleral vein isolated from the surrounding tissues; a cautery specifically applied to the selected vein). Now, medication (pentadecapeptide BPC 157 (10μg/kg) (Diagen, Slovenia) intraperitoneally) or an equivolume of 0.9%NaCl (5ml/kg) intraperitoneally (controls)) was immediately after surgery, and then once time daily. Non‐invasive IOP measurements (% of normal IOP) (after local application of Tetrakain 0.5%, by aplanation tonometer Tonopen XL always at 9.00 a.m.), and papilla nervi optici were assessed throughout 3 or 6 months after procedure. Vascularization of the eye fundus and presentation of papilla n. optici were analyzed with microcamera (Veho USB Discovery VMS‐004) and Digital Widefield lupe 90D. We focused on the vessels extending into and out of the optic disc, retinal changes alterations in vessel caliber and tortuosity, optic disc pallor and leakage of the retinal arterioles and venulas, scored (1–3), as described before (The FASEB Journal, Vo. 30 No.1 supplement 1201.4).ResultsAt 3 months after surgery controls exhibited increased values (IOP=134±5%) while BPC 157 remained values close to normal IOP=104±4%. At 6 months after surgery control rats maintained the increased values IOP=133±6%. BPC 157 exhibited normal IOP=106±5%. All BPC 157‐rats exhibited only slight generalized vessel caliber irregularity (difference in diameter between arteries and veins) with a vaguely atrophic optic disc and an area not bigger than 1 optic disc diameter containing leaking of retinal vessels (Min/Med/Max 1/1/1) (Figure 1). Controls exhibited increased disturbances: either moderate generalized vessel caliber irregularity (bigger difference in diameter between arteries and veins with moderate overfilling of veins) Min/Med/Max 2/2/3; with moderate atrophic optic discs Min/Med/Max 2/2/3; and an area not more than 3 optic disc diameters containing leaking of retinal vessels Min/Med/Max 2/2/3; or severe generalized vessel caliber irregularity (very big difference in diameter between arteries and veins with severe overfilling of veins) with severe atrophic optic disc and an area more than 3 optic disc diameters with leaking of retinal vessels (all Min/Med/Max 3/3/3) (Figure 2). Microscopy analysis correlates well with ophthalmoscopy findings (i.e., BPC 157 groups diameter of the optic nerve remained close to normal unlike control's atrophy/thinning of the optic nerve).ConclusionPentadecapeptide BPC 157 continuously counteracts the effects of episcleral vein cauterization.Support or Funding InformationUniversity of Zagreb, Zagreb, Croatia (Grant number BM099)Ministry of Science, Education and Sports, Republic of Croatia (Grant number 108‐1083570‐3635)