Table 2.

Mouse lines with downstream disruption of GH action. Summary of the reported mouse lines with a disruption downstream of GHR that inhibits normal GH signaling. Selected phenotypes are included, such as serum GH and IGF-1 levels, body size and weight, bone growth, insulin sensitivity, reproductive capacity, and cancer incidence. Blank cells indicate parameters that were not reported.

Mouse lines	GH level	IGF-1 level	Body size / Weight	Body composition	Bone growth	Insulin sensitivity	Reproductive capacity	Cancer incidence	Other notes	References
JAK2 KO							Lethal		Erythropoiesis impaired	[75]
STAT5b KO	↑ (male only)	↓ (both sexes)	↓ (males only)	↓ adipose tissue	↓ (males only)		Poor lactation; deficient pregnancy	Varies by genetic background	Delay of hair growth; GH pulse-resistant	[69, 70, 76, 77]
SOCS2 TG			↑	↓ adipose tissue			Fertile			[71]
SOCS2 KO		↑ local IGF-1; no difference in serum	↑	↔	↑		↔		Thickening of dermis; excessive collagen deposition	[78, 79]
ALS KO	↔	↓ serum IGF-1 and IGFBP3	↓		↓ bone mineral density	↔	↔			[80, 81]
IGF-1 KO		Below detection limits	↓		↓		Infertile		High neonatal lethality (less than that of IGFR −/−), only 68% reach adulthood	[82, 83]
IGFBP3-KO	↔	↔; ↓	No change at birth; ↑ overall weight	↑ muscle mass; ↓ WAT mass		↑ fasting blood glucose, ↑ insulin, impaired GTT	↔	↑lung cancer progression	↓ plasma TG adiponectin levels;↓ metabolic rate	[84–86]