The species barrier that forced the pituitary era, and the single receptor residue behind it

Published 26 October 2026 · REVIVE LAB UAE Research Desk · 5 min read
Non-primate growth hormones — bovine, porcine, ovine — do not activate the human receptor, while human growth hormone activates the receptors of most mammals. This one-way barrier meant that before recombinant production the only source for clinical use was human pituitary tissue. Work in the 1990s traced the barrier largely to a single interaction: a histidine at position 171 in non-primate hormones clashes with an arginine at position 43 of the primate receptor, where the primate hormone carries aspartate and forms a salt bridge instead.

The observation

Early attempts to treat growth hormone deficiency with animal hormone failed, while animal hormone worked in animals and human hormone worked in both. The pattern defined the species specificity and set the agenda of the pituitary collection programmes. It also explained why growth hormone was late to the clinic compared with insulin, where pig and cow hormone sufficed.

The specificity is at the receptor, not in downstream signalling.

The molecular basis

Primate growth hormones carry aspartate at position 171; non-primate hormones carry histidine. The primate receptor carries arginine at position 43, which pairs with the aspartate and is repelled by the histidine. Replacing the single residue in either partner transfers the specificity, which was shown by mutagenesis in the mid-1990s. The remainder of the barrier comes from a few further contacts.

It is one of the clearest examples of a species barrier reduced to a single salt bridge.

Why it matters here

The product is human-sequence somatropin because only the human sequence acts on the human receptor, and that same fact is why the hormone had to be recombinant. The history on the 1985 page follows from it.

Somatropin is supplied by REVIVE LAB UAE for laboratory research use only, with identity and purity documented for the batch. It is not for human or veterinary use, and no dosing, administration or protocol guidance is provided.

What it costs

FormatStrengthPriceAvailability
HGH Somatropin Pack24 mg (72 IU)AED 850In stock

Delivery is AED 40 flat and free on orders over AED 700. Payment is cash on delivery anywhere in the UAE, or USDT (TRC20) in advance, which takes 5% off the order total.

Frequently asked

The observation?

Early attempts to treat growth hormone deficiency with animal hormone failed, while animal hormone worked in animals and human hormone worked in both. The pattern defined the species specificity and set the agenda of the pituitary collection programmes. It also explained why growth hormone was late to the clinic compared with insulin, where pig and cow hormone sufficed.

Does REVIVE LAB UAE provide dosing guidance?

No. REVIVE LAB UAE supplies research materials and provides no dosing, administration or protocol guidance of any kind. Every product is sold for laboratory research use only and is not for human or veterinary consumption.

How fast is delivery in the UAE?

Stock is held in Dubai. An order confirmed before 4 PM Dubai time is dispatched the same working day, reaching Dubai and Abu Dhabi the same day and the remaining emirates within 24 hours. Delivery is AED 40 flat and free over AED 700.

HGH Somatropin Pack — in stock, dispatched from Dubai
HPLC-verified, lot certificate on every carton, 24-hour delivery nationwide. Browse the catalogue → All peptides UAE

Related reading

Supplied for laboratory research use only. Not for human or veterinary consumption. REVIVE LAB UAE provides no dosing, administration or protocol guidance.