Growth hormone stimulates islet B-cell replication in neonatal rat pancreatic monolayer cultures

Abstract

A possible role for growth hormone (GH) in stimulating islet B-cell replication was examined in neonatal rat pancreatic monolayer cultures.

Addition of ovine GH (1000 ng/ml) to serum-free medium for 2 days resulted in a significant increase (+114%) in [3H]thymidine labeling of B-cells in aldehyde-thionine-stained autoradiographs, and a similar increase in the B-cell mitotic index.

The stimulatory effects of GH on islet B-cell replication were greatest in serum-free medium, unaffected by glucose concentrations (2.8--16.7 mM), and not accompanied by any stimulation of insulin release.

The threshold concentration of GH for a significant stimulatory effect on B-cell replication was 30 ng/ml.

The insulin-like growth factor, multiplication stimulating activity (MSA), also effectively stimulated B-cell replication.

Although some effects of GH are mediated by the insulin-like growth factors (IGFs), the effects of GH on B-cell replication did not appear to be mediated by IGFs since (1) the maximal effect of GH (+156%) was significantly greater than that of MSA (+91%); (2) the combination of maximal stimulatory concentrations of GH and MSA produced an additive effect; and (3) a significant effect of GH on B-cell replication was observed as early (8 h) as that produced by MSA.

These results suggest that GH can stimulate islet B-cell replication directly, and that this effect may not depend on production of either insulin-like growth factors.

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See also:

- Official Web Site: The Di Bella Method;

- Somatostatin in oncology, the overlooked evidences - In vitro, review and in vivo publications;

- The Di Bella Method (A Fixed Part - Somatostatin, Octreotide, Sandostatin LAR, analogues and/or derivatives);

- The Di Bella Method (A Fixed Part - Bromocriptine/Cabergoline);

- The Di Bella Method (A Fixed Part - Cyclophosphamide and/or Hydroxyurea tablets, one or two per day);

- Pancreatic Adenocarcinoma: clinical records on 17 patients treated with Di Bella's Method;

- The Di Bella Method Increases by the 30% the survival rate for Pancreas tumors and for this reason should be proposed as first line therapy for this type of cancer.