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Sermorelin, Growth Hormone Releasing Hormone (1-29), hGRF(1-29)NH2
A synthetic peptide analog of growth hormone-releasing hormone that stimulates the pituitary gland to secrete growth hormone.
Michalkiewicz. M M; Huffman. L J LJ; Hedge. G A GA
Scientists tested three chemicals that were supposed to block a hormone called VIP, to see if they could change blood flow in the thyroid gland of rats. The drugs didn't affect thyroid blood flow or hormone release, even at much higher doses than the hormone itself. This means those particular blockers don't work for influencing thyroid blood flow.
Zhang. C Y CY; Yamasaki. R R; Mitsuhashi. S S; Takahashi. H H; Bando. H H; Saito. S S
Scientists created a very sensitive blood test to measure the hormone GHRH and used it to see how much of the hormone is in healthy people and in several disease groups. They found normal levels around 20 ng/L, higher levels in kidney‑failure patients, and extremely high levels in a rare tumor case. The study mainly shows the test works, not how to use GHRH for performance or health.
Wiesenfeld-Hallin. Z Z; Xu. X J XJ; Håkanson. R R; Feng. D M DM; Folkers. K K
In rats, tiny amounts of morphine injected into the spine make a reflex stronger by causing the release of different brain chemicals, depending on whether the leg nerves are still connected. When the nerves are intact, the chemical substance P is involved; when the nerves are cut, a different chemical called VIP takes over. A peptide called GRF‑1‑29 was used to block VIP and stop the reflex boost in the nerve‑cut rats.
Xu. X J XJ; Wiesenfeld-Hallin. Z Z
In rats, a modified growth‑hormone‑releasing‑factor peptide (Ac‑Try1, D‑Phe2‑GRF‑1‑29) blocks the pain‑enhancing effects of vasoactive intestinal peptide (VIP) in the spinal cord, showing it works as a specific VIP antagonist but doesn’t affect other pain‑related signals.
Blank. M A MA; Kimura. K K; Fuortes. M M; Jaffe. B M BM
Scientists tested a modified peptide called [N-Ac-Tyr1,D-Phe2]-GRF-(1-29)-NH2 in anesthetized cats and found it can blunt the widening of blood vessels in the colon that normally happens when certain nerves are stimulated. The peptide didn’t change the amount of the natural signaling molecule VIP that was released, just blocked its effect on blood flow.
Wiesenfeld-Hallin. Z Z; Xu. X J XJ; Håkanson. R R; Feng. D M DM; Folkers. K K
In rats, a peptide called GRF‑1‑29 (used as a VIP blocker) can stop a certain spinal reflex that normally gets stronger after nerve injury. The study shows that after cutting a nerve, the body switches from using one type of signaling molecule (tachykinins) to another (VIP) to boost that reflex.
Venugopalan. C S CS; Holmes. E P EP; O'Malley. N A NA
In guinea‑pig trachea, the peptide VIP makes the airway muscles relax. Two synthetic versions of a related peptide (one based on GRF‑1‑29) can block this relaxation, but only at relatively high concentrations. The study shows how these compounds interfere with VIP’s effect in a lab setting.
Nielsen. F C FC; Gammeltoft. S S; Westermark. B B; Fahrenkrug. J J
The study shows that the hormone VIP sticks tightly to receptors on a type of brain cancer cell, gets pulled inside the cell, and is broken down. Some specially modified versions of the growth‑hormone‑releasing peptide (GRF‑1‑29) can block VIP from binding, but only at fairly high concentrations. The findings are mostly about cell‑culture chemistry and don’t give clear guidance for everyday supplement or dosing strategies.
Andler. W W; Eiden. S S
The study looked at using a short version of growth‑hormone‑releasing factor (GRF‑1‑29) to test if kids have growth‑hormone problems. It found the test is good at confirming normal pituitary function but often gives false positives for hypothalamic issues, so it isn’t reliable for diagnosing growth‑hormone deficiency.
Hocart. S J SJ; Murphy. W A WA; Coy. D H DH
Scientists tried swapping a normal peptide bond for a special chemical link in a growth‑hormone‑releasing peptide (GRF‑1‑29) to see how it changes activity. Most of the modified versions barely activated the hormone release, and one version actually blocked the natural peptide at relatively high concentrations.
Cauvin. A A; Buscail. L L; Gourlet. P P; De Neef. P P; Gossen. D D; Arimura. A A; Miyata. A A; Coy....
The study shows that the brain peptide PACAP binds strongly to specific receptors on human neuroblastoma cells, while similar peptides like VIP are much weaker and the growth hormone‑releasing peptide GRF‑1‑29 does not bind these receptors at all.
Greco. A V AV; Mancinelli. R R; Mingrone. G G; Racanicchi. C C
In guinea pig gallbladders, a peptide called GRF‑1‑29 (a glucagon‑secretin family member) makes the muscle contract more strongly and often, while blocking VIP (another gut peptide) does nothing. This suggests that the natural nerve signal that relaxes the gallbladder isn’t VIP but something like GRF‑1‑29.
Pinilla. L L; López. F J FJ; Aguilar. E E
In rats, the ability of the pituitary gland to release growth hormone (GH) after a GHRH injection changes with age and whether the testes are removed. Removing the testes early (when the rats are young) makes the pituitary more responsive to GHRH a week later, while removing them later (when the rats are older) reduces the response. Overall, the age‑related increase in GH response happens regardless of testicular function.
Armstrong. J D JD; Esbenshade. K L KL; Coffey. M T MT; Heimer. E E; Campbell. R R; Mowles. T T; Feli...
In nursing mother pigs, blocking the hormone GRF‑1‑29 with a vaccine lowered their growth hormone (GH) levels, and giving an opioid blocker (naloxone) also reduced GH and prolactin. The study shows that opioids can influence GH both through GRF‑dependent and independent routes, but it was done in sows, not humans.
Nurko. S S; Rattan. S S
In opossums, the peptide VIP makes the internal anal sphincter relax, and a modified GRF peptide can block this effect. The study shows that VIP directly lowers sphincter pressure and that blocking VIP reduces the natural reflex that relaxes the sphincter by about half.
Jordan. V V; Dieguez. C C; Valcavi. R R; Artioli. C C; Portioli. I I; Rodriguez-Arnao. M D MD; Gomez...
In people with acromegaly (a condition with too much growth hormone), blocking muscarinic cholinergic receptors with the drug pirenzepine did not change how their bodies responded to the growth‑hormone‑releasing peptide GRF‑1‑29 or to TRH. This is different from what happens in healthy people, where such blockade can lower the hormone response.
Ranke. M B MB; Blum. W F WF; Haug. F F; Rosendahl. W W; Attanasio. A A; Enders. H H; Gupta. D D; Bie...
The study looked at growth hormone (GH) and related proteins in girls with Turner syndrome, a rare genetic condition. It found that the basic GH system works normally, but the levels change over time because these girls lack normal ovarian hormones. Some individuals may still have unusually low GH or IGF levels.
Coxam. V V; Davicco. M J MJ; Opmeer. F A FA; Ravault. J P JP; Barlet. J P JP
In newborn calves, injecting the short version of growth hormone‑releasing factor (GRF‑1‑29) makes the pituitary release more growth hormone (GH), but it doesn't change the downstream hormone IGF‑1 or blood sugar. A similar hormone, TRH, also boosts GH and other hormones, but the effect is weaker in slightly older calves.
Robberecht. P P; Coy. D H DH; Waelbroeck. M M; Heiman. M L ML; de Neef. P P; Camus. J C JC; Christop...
Scientists tested many versions of the growth‑hormone‑releasing peptide (GRF) to see how changes in its building blocks affect its ability to turn on an enzyme in rat pituitary cells. They found that swapping a specific amino‑acid at position 2 to its mirror‑image form (D‑Arg) made the peptide work even better, while the same swap in a slightly modified version turned the peptide into a blocker that stops the normal GRF from working.
Chakder. S S; Rattan. S S
The study shows that the full vasoactive intestinal peptide (VIP) molecule is needed to relax gut smooth muscle, while shorter pieces and a growth‑hormone‑releasing‑factor (GRF) analog can stick to the VIP receptor but do not really relax the muscle.