title: Endogenous production of hydrogen sulfide in isolated bovine eye.
abstract: Hydrogen sulfide (H(2)S) is a novel gasotransmitter with physiological and pathological functions in vascular homeostasis, cardiovascular system and central nervous system. In the present study, we determined the endogenous levels of H(2)S in various tissues of the bovine eye. We also examined the basal levels of H(2)S in response to donors (sodium hydrosulfide, NaHS and sodium sulfide, Na(2)S), substrate (L: -cysteine), inhibitors (propargylglycine, PAG and aminooxyacetic acid, AOA) and activator (S-adenosyl-L: -methionine, SAM) of this gas in the bovine retina. H(2)S was measured using a well established spectrophotometric method. The highest concentration of endogenous H(2)S was detected in cornea (19 ± 2.85 nmoles/mg protein, n = 6) and retina (17 ± 2.1 nmoles/mg protein, n = 6). Interestingly, H(2)S was not present in vitreous humor. The inhibitors of CSE and CBS; PAG (1 mM) and AOA (1 mM), significantly attenuated the production of H(2)S in the bovine retina by 56.8 and 42%, respectively. On the other hand the activator of CBS; SAM (100 μM), H(2)S donors; NaHS (1 μM) and Na(2)S (100 μM), significantly increased endogenous levels of H(2)S in bovine retina. L: -cysteine (10-300 μM) produced a significant (P < 0.05) concentration-dependent increase in H(2)S levels reaching a maximal at 300 μM. We conclude that H(2)S is endogenously produced in various tissues of the isolated bovine eye. Moreover, endogenous levels of H(2)S are enhanced in the presence of substrate (L: -cysteine), an activator of CBS (SAM) and H(2)S donors but are blocked by inhibitors of enzymes that synthesize this gas in neural retina.
authors.affiliation: Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, Texas Southern University, Houston, TX 77004, USA.
authors.forename: Madhura
authors.initials: M
authors.lastname: Kulkarni
authors.forename: Ya Fatou
authors.initials: YF
authors.lastname: Njie-Mbye
authors.forename: Ikechukwu
authors.initials: I
authors.lastname: Okpobiri
authors.forename: Min
authors.initials: M
authors.lastname: Zhao
authors.forename: Catherine A
authors.initials: CA
authors.lastname: Opere
authors.forename: Sunny E
authors.initials: SE
authors.lastname: Ohia
mesh_terms: D000818:Animals; D002417:Cattle; D003541:Cystathionine beta-Synthase / Q000378:metabolism; D003542:Cystathionine gamma-Lyase / Q000378:metabolism; D003545:Cysteine / Q000494:pharmacology; D005123:Eye / Q000033:anatomy & histology* / Q000187:drug effects / Q000378:metabolism*; D006862:Hydrogen Sulfide / Q000378:metabolism*; D018377:Neurotransmitter Agents / Q000378:metabolism; D012160:Retina / Q000187:drug effects / Q000378:metabolism
chemical_list: D018377:Neurotransmitter Agents; D003541:Cystathionine beta-Synthase; D003542:Cystathionine gamma-Lyase; D003545:Cysteine; D006862:Hydrogen Sulfide