A protein from urutu snake venom could be beneficial to the heart

In vitro tests show that alternagin-C can increase the force of heart contractions and has a pharmacological potential.

By Karina Toledo

Agência FAPESP – In vitro tests conducted at Universidade Federal de São Carlos (UFSCar) indicate that alternagin-C (ALT-C), a protein extracted from urutu (Bothrops alternatus) snake venom, can increase the force of heart contractions and has a pharmacological potential.

The protein is being tested in the myocardia of mice and fish during the post-doctoral studies of FAPESP fellow Diana Amaral Monteiro under the supervision of Professor Francisco Tadeu Rantin, in collaboration with Heloisa Sobreiro Selistre de Araújo and Ana Lúcia Kalinin.

Monteiro presented her preliminary results during the 28th Annual Meeting of the Federation of Experimental Biology Societies (FeSBE), conducted in August at Caxambu (MG).

“If positive results are confirmed in the future, this protein could be useful in the treatment of such diseases as cardiac insufficiency, heart attack and chronic cardiac ischemia,” affirmed Monteiro.

ALT-C was initially isolated during a FAPESP-funded study coordinated by Araújo. The method for obtaining the molecule has been patented because of its ability to induce angiogenesis (the formation of new blood vessels).

“As previous studies showed that the protein promotes revascularization and regeneration in damaged rat skin, this sparked the idea that it might also have a beneficial effect on the cardiovascular system,” explained Monteiro.

In tests conducted previously, Monteiro administered a single intra-arterial dose of ALT-C to the wolf fish (Hoplias malabaricus), and the in vitro contractility of isolated ventricular strips of the wolf fish heart was analyzed after seven days. ALT-C caused a significant increase in the force of myocardial contraction and in the rates of contraction and relaxation, positively modulating cardiac contractility.

“We are still going to study the mechanisms responsible for improving cardiac function. But we know that this protein is connected to an integrin-type receptor (a protein found on cell surfaces) and that this sets off a series of intracellular signals capable of promoting gene activation and increasing the production of vascular endothelial growth factor (VEGF), which is involved in angiogenesis,” explained Monteiro.

The next step in the investigation, according to the researcher, will be to evaluate the mechanism underlying the effects of this protein on heart contractions in mice.

During the FeSBE meeting, Monteiro also presented the results of her doctoral project, advised by Kalinin.

In this project, Monteiro investigated the effect of different routes of mercury contamination on the Brazilian wolf fish and matrinxã (Brycon amazonicus) and observed that the metal adversely affects both the heart’s contractility and pumping capacity and the animal’s cardiorespiratory responses at normal concentrations of oxygen and in situations of hypoxia (low concentrations of dissolved oxygen).

The findings were published in Aquatic Toxicology and Ecotoxicology.